Tool for truing contact points



May 5, 1925.

N. A. ANDERSON TOOL FOR TRUING CONTACT POINTS Filed June 12, 192,4

@5G-Ma@ NT R @ZA/a AITQRNEY Patented May 5, 1925.

NILS A. ANDERSON, OF BROOKLYN, NEW YORK.

TOOL FOR TRUING CONTACT POINTS.

Application led June 12, 1924. Serial No. 719,515.

To all whom it may concern.'

Be it known that I, NILs ALFRED ANDER- soN, a subject of the King of Sweden and an applicant for citizenship of the United States, and a resident of the borough of Brooklyn, city and State of New York, have invented certain new and useful Improvements in rIools for Truing Contact Points, of which the following is a specification.

My invention relates to a novel tool for holding the small lever used in the timing Vdevices of automobile and other engines, to

permit the contact pointof the said lever to be reground in order to make its contact surface fiat and true. The present invention is of the same general character as that shown in Letters Patent No. 1,453,459 June 12, 1923, issuedto me. The contact point employed in engines having electric ignition systems, although made of very hard metal, become pitted due to arcing and to lack of accurate Contact between these points, imperfect ignition in the motor results, and this reduces the efficiency of the motor. The present tool is adapted to hold the contact lever of part of the ignition system of a vgasoline motor, so that the contact point of the lever may be reground by means of a small stone to make the surface of the point smooth and to correct any error in the angle of its contact fa.ce,.so that it will make perfeet Contact with the contact point `with which it cooperates. The object of the present invention isto provide simple means for holding and adjusting the contact lever in relation to the tracks which guide the grinding stone so that t-he contact point of the Vlever may be reground a number of times and at the Same angle'. l

In the drawing forming part of this application,

Figure 1 is a plan view of my improved tool with the contact lever omitted, p

` Figure 2 is a longitudinal, sectional view of the tool showing the contact lever in position for the regrinding operation,

Figure 3 is a partial longitudinal sectional view showing the parts in the position ready to receive the contact lever,

Figure t is a cross sectional view taken on the line 4 4 of Figure 2, and

Figure 5 is a perspective view of the clamp for holding the contact lever.

I have shown in the drawing a tool consisting in part of a base 1 having a channel 2 extending longitudinally through the center of the tool and at opposite sides of this channel there are raised parallel walls 3, 4; which are preferably lined on the top surfaces with plates 5 of hardened steel which are secured to these walls by means of screws 6 countersunk in the top surfaces of the plates or tracks. These plates 5 form tracks lying in a common plane and the grinding stone (not shown) is adapted to be limited by these tracks in order to control the angle to which the contact point is finally ground. Between the tracks I have shown a number of vertically extending apertures 7 through which the plain Contact screws of the ignition system of an automobile may be inserted in the same manner as is shown in my said patent, and the upper ends of these aper-` tures terminate at different levels corresponding with the stepped` resting surfaces 8 against which the heads of the contact screws may rest. The contact screw may be inserted in any one of these apertures 7 according to the length of the contact point of the screw.I and the contact point may be positioned slightly above the plane of the tops ofthe tracks and they -are ground down with the use of a stone in the manner shown and described in my said patent.

Near the opposite end of the tool the side walls 3, 4t are provided with slots 9, 10 which are inclined in parallel relation with the inclined bottom surface11 formedv in the lower portion of the base. In one 4of the side walls there is a groove 12 adjacent` the end of one of the inclined slots 9, to permit`v the insertion of the contact lever. The contact lever of the type shown in the drawing comprises an arm 13 having a block of in sulating material 1li fixed against the side of the arm intermediate its ends; and on a free end of the arm there is a contact point 15 usually made of hard metal. The arm, which is curved, has a pin or shaft 16 fixed at one end, together with a bearing member' 17 on this shaft. One end of the shaft 16 projects at one side of the arm in the form of a rounded head 18 `and the other end of the shaft projects beyond the bearing member`17. In the construction of the tool shown herein the walls 3, 4f which contain theinclined slots 9, 10are spaced closer than the length of the shaft 16 of the lever and in order to position the lever between these walls with the shaft 16 of the lever.

extending into one of these slots, it is necessary to insert the lever from the right hand end of the slots in Figures 1, and 2, and the groove 12 is formed to permit the end of thc shaft 16 to be moved into position to pass into one of the slots, 9.

There is a holder 2O which is shown detached in Figure 5, and which may be stamped from sheet metal. It comprises a yoke including an arm 21 having an open slot to receive the shaft 16 of the contact arm, and there is a projection 23 on one side of this slot to guide the shaft therein. This arm 21 is opposite to and parallel with another arm 2l the two arms being` connected by the cross member 25. The arm Q1 has a stud Q6 which projects through onev of the inclined slots 10, and exterior of the wall et there is a nut 27 threaded on the stud 26 for the purpose of clamping` the holder 2() in different positions along the walls'l, Ll.' The inner end of the stud Q6 is provided with a depression or socket 2S to receive the rounded end 18 of the shaft 1G of the contact arm. The connecting member of the holder projects outwardly at Q9 and is then bent at ri ghtangles to form an arm 30 which is adapted to press down on the contact arm 13 to hold the block 11 of the latter in close engagement with the inclined surface 11 of the base.

O peru-tion.

To insert the contact arm into the tool, the holder 2O isvswung to the position shown in Figure 3 which will bring the slot 22 in alignment with the inclined slots 9, 1() of the side walls. The contact arm is moved in an angular position between the walls lA so that the outer end of the shaft 16 passes through the groove 12, whereupon the contact arm is straightened, parallel with the tool, the free end ofthe shaft 1G entering the slot 9, The contact arm is then moved toward the holder 2O until the free endV of the shaft enters the slot 22 of the member 21 and the rounded end 1S of the shaft snaps into the depression 28 on the end of the stud QG. The holder is then swung over until the arm 30 engages the top of the contact arm and this movement causes the member 21 to turn on the end of the shaft 1G so that the latter is then locked b v the wall 3, and by the member 21 and remains so as long as the holder is in the position shown in Figure 2. The holder and contact arm are then moved lengthwise of the base, either forwardly or backwardly, and as the block 1st slides along the inclined surface 11, the top of the contact point 15 will be raised or lowered according to Iwhether the arm is moved to the right or left in Figure and the contact arm will maintain a definite angular position in rey lation to the plane of the tracks 5, because the surface. 11 and the inclined slots 3, 4 are parallel. with each other. When the contact arm is so adjusted that the contact point 15 projects slightly above the plane of the tracks, the nut 2T is tightened to secure the holder in place. The operator may hold the tool with one hand, pressing down on the arm 29 with one finger or thumb to prevent the contact arm from swinging, and he moves a grinding stone over the surface of the contact point 15 until the latter has been ground down to a point where the stone rest-s on both tracks. This will reface the contact point, the surface being parallel to its original contactsurface, and the operation may be repeated whenever the contact point has become worn or pitted. To release the contact arm, the holder 2() is swung into the position. shown in Figure 3, which brings the slot 22 in line with the slot 9 and the shaft 1G may then be moved out of the slot 22 and the contact arm may be tilted and removed.

Having described my invention, what l claim is:

1. A tool for refacing contact points of ignition levers, comprising a base having tracks for guiding` a grinding stone said base having a guiding` surface inclined relatively to the plane of the tracks for guiding the lever, spaced walls having slots extendingl parallel to said guiding surface, and a. lever holder guided in one of said slots and adapted to hold a lever having its shaft projecting into the other of said slots.

2. A tool for refacing contact points of lever arms, comprising a base having tracks for guiding a grinding stone, said base having a guiding surface inclined relatively to the plane of the tracks for guiding the lever. spaced walls having slots extending parallel to said guiding surface, and a lever holder guided in one of said slots and having a slot to receive the shaft of the lever, said holder being adapted to be rocked to position its slot to receive said shaft and to lock the same, said holder being adapted to hold the lever in position to engage said inclined surface.

3. A tool for refacing contact points of lever arms, comprising a base having tracks for guiding' a grinding stone, said hase having a surface inclined relatively to the plane of the tracks to guide the lever, spaced walls having` slots extending parallel with said guiding surface, a rocking lever holder having a stud guided in one of said slots, said holder having a slot to receive the shaft of the lever in one position and to lock the same therein when the holder is rocked, the shaft of the lever being received in the other slot of said spaced walls.

4. A tool for refacing contact points of lever arms, comprising a base having tracks for guidinga grinding stone, said base having a surface inclined relatively to the plane of the tracks to guide the lever, spaced walls having slots extending parallel with said guiding surface, a rocking holder having a stud guided in one of said slots, said holder having means for engaging and holding the shaft of the contact lever, said holder having an arm `for engaging the contact lever to hold it in engagement with said guiding surface.

5. A tool for refacing contact points of lever arms comprising a base having tracks for guiding' a grinding stone, said base having a surface inclined relatively to the plane of the tracks to guide the lever, spaced walls having slots extending parallel With s'aid guiding surface, a rocking holder having a stud guided in one of said slots, said holder having a slotted arm to receive and hold the shaft of the contact lever, said stud having a recess in Which the end of said shaft may engage, said holder being adapted to hold the contact lever in relation to said guiding surface.

6. A tool for refacing contact points. of lever arms, comprising a hase having tracks for guiding a grindino stone, said hase lia-ving a surface inclined relatively to the planeV of the tracks to guide the lever, spaced Walls having slots extending parallel With said guiding surface, a rocking holder having spaced parallel arms, a stud on one of said arms guided in one of said Wall slots, the other holder arm having a slot to receive the sha-ft of the lever arm, said holder having an arm adapted to he hand pressed and tohold the contact lever against said inclined surface. e Y

Signed at the city, county and State of New York, this 4th day of June, 1924.

NILS A. ANDERSON. 

